Printers for printing information on discrete, flexible substrates such as plastic identification cards, drivers licenses, prepaid cards, and the like, conventionally comprise a substrate hopper and feeder for storing and supplying a succession of individual substrates to be printed; a substrate cleaning station for cleaning the surface of each substrate prior to printing; a print station typically comprising a thermal printhead cooperating with a thermal transfer ribbon or dye sublimation ribbon to print the information on the information-receiving surface of the substrate; and a discharge station for receiving the printed substrates.
The thermal printhead is actuated by a drive mechanism to move the head toward and away from a platen roller in synchronization with the sequential transportation of the substrates past the print station. Printing is effected through the thermal transfer or dye sublimation ribbon positioned between the printhead and the substrate. The thermal printhead has a transverse tip carrying a large number of heatable elements selected ones of which are energized to transfer an ink or a dye from the ribbon to the substrate. The ribbon is typically carried by a replaceable ribbon cartridge that is disposed of when the ribbon is spent.
As is known, the printable surface of information-bearing substrates and particularly those in the form of cards made of plastics such as PVC, must be clean so as to provide a high quality representation of the printed information (and particularly so where the information is applied by a high temperature thermal printing process) and to protect the printhead from being damaged. A substrate cleaning station is therefore provided upstream of the printing station. The cleaning station typically comprises a cleaning platen roller that rides in contact with the information-receiving surface of each of the substrates successively fed through the printer. The cleaning platen roller has a surface of, for example, silicone, treated to make the surface tacky so as to lift particulate matter such as dust and/or other debris (hereinafter “debris”) from the print-receiving substrate surface. It will be evident that as the tacky surface of the cleaning roller accumulates debris the roller will lose its effectiveness so that the cleaning roller itself needs to be kept clean. Alternatively, the cleaning roller must be replaced when the tacky surface becomes saturated with debris.
In one approach, the tacky cleaning roller is periodically cleaned by means of a sticky debris removal member in the form of a sticky tape fed from a tape supply roll against the surface of the tacky cleaning roller and from there to a tape take-up roll. The sticky tape supply and take-up rolls are carried by a tape carrier. When the sticky tape is consumed, the tape carrier is disposed of and replaced. In another conventional approach, a sticky removal member in the form of a sticky roller riding in contact with the surface of the tacky cleaning platen roller is used to clean the platen roller. When the sticky roller loses its effectiveness it is disposed of and replaced.
Thus, in conventional substrate printers, both the sticky removal member and the ribbon cartridge must be separately removed and individually replaced. It has been found, however, that most end users neglect to change the sticky removal member when it loses its debris-lifting effectiveness. As a result, debris remaining on the substrate surface can enter the print mechanism causing poor print quality and ultimately leading to the destruction of the printhead that is the most expensive component of the printer.